1. Field of the Invention
The present embodiment relates to a phosphor that produces fluorescence when excited by exposure to excitation light and, in particular, an Al2O3—SiO2-based oxide phosphor.
2. Description of the Related Art
Phosphors that produce visible light when excited by exposure to near-ultraviolet light are used in, for example, luminescent apparatuses constituted of such a phosphor and a source of near-ultraviolet light, such as a semiconductor LED device, in combination therewith (e.g., see Japanese Unexamined Patent Application Publication No. 2007-103512).
However, such phosphors have some problems. For example, they are based on expensive complex oxides of decreasing availability or otherwise unsatisfactory in terms of durability.
This unsatisfactory situation causes demand for a novel phosphor that is highly durable and produces visible light when excited by exposure to near-ultraviolet excitation light.